From: Ted Kremenek <kremenek@apple.com>
Date: Fri, 24 Apr 2009 21:56:17 +0000 (+0000)
Subject: Fix the same false positive reported in PR 2542 and <rdar://problem/6793409>
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=8ee885bae5e8b187a73f3d4671b1619969e5e080;p=clang

Fix the same false positive reported in PR 2542 and <rdar://problem/6793409>
involving an NSAnimation object delegating its release to a delegate method.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@69992 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/CFRefCount.cpp b/lib/Analysis/CFRefCount.cpp
index 7b16007a7a..4961ef47fc 100644
--- a/lib/Analysis/CFRefCount.cpp
+++ b/lib/Analysis/CFRefCount.cpp
@@ -1074,8 +1074,8 @@ RetainSummaryManager::getInitMethodSummary(ObjCMessageExpr* ME) {
 
 
 RetainSummary*
-RetainSummaryManager::getCommonMethodSummary(ObjCMessageExpr* ME, Selector S)
-{
+RetainSummaryManager::getCommonMethodSummary(ObjCMessageExpr* ME, Selector S) {
+
   if (ObjCMethodDecl *MD = ME->getMethodDecl()) {
     // Scan the method decl for 'void*' arguments.  These should be treated
     // as 'StopTracking' because they are often used with delegates.
@@ -1091,12 +1091,26 @@ RetainSummaryManager::getCommonMethodSummary(ObjCMessageExpr* ME, Selector S)
       }
   }
   
+  // Any special effect for the receiver?
+  ArgEffect ReceiverEff = DoNothing;
+  
+  // If one of the arguments in the selector has the keyword 'delegate' we
+  // should stop tracking the reference count for the receiver.  This is
+  // because the reference count is quite possibly handled by a delegate
+  // method.
+  if (S.isKeywordSelector()) {
+    const std::string &str = S.getAsString();
+    assert(!str.empty());
+    if (CStrInCStrNoCase(&str[0], "delegate:")) ReceiverEff = StopTracking;
+  }
+  
   // Look for methods that return an owned object.
   if (!isTrackedObjectType(ME->getType())) {
-    if (ScratchArgs.empty())    
+    if (ScratchArgs.empty() && ReceiverEff == DoNothing)
       return 0;
     
-    return getPersistentSummary(RetEffect::MakeNoRet());
+    return getPersistentSummary(RetEffect::MakeNoRet(), ReceiverEff,
+                                MayEscape);
   }
   
   // EXPERIMENTAL: Assume the Cocoa conventions for all objects returned
@@ -1108,7 +1122,7 @@ RetainSummaryManager::getCommonMethodSummary(ObjCMessageExpr* ME, Selector S)
                      : RetEffect::MakeOwned(RetEffect::ObjC, true))
       : RetEffect::MakeNotOwned(RetEffect::ObjC);
   
-  return getPersistentSummary(E);
+  return getPersistentSummary(E, ReceiverEff, MayEscape);
 }
 
 RetainSummary*
diff --git a/test/Analysis/pr_2542_rdar_6793404.m b/test/Analysis/pr_2542_rdar_6793404.m
new file mode 100644
index 0000000000..82a028d652
--- /dev/null
+++ b/test/Analysis/pr_2542_rdar_6793404.m
@@ -0,0 +1,68 @@
+// RUN: clang-cc -analyze -checker-cfref -pedantic -analyzer-store=basic -verify %s &&
+// RUN: clang-cc -analyze -checker-cfref -pedantic -analyzer-store=region -verify %s
+
+// BEGIN delta-debugging reduced header stuff
+
+typedef signed char BOOL;
+typedef unsigned int NSUInteger;
+typedef struct _NSZone NSZone;
+@class NSCoder;
+@protocol NSObject
+- (BOOL)isEqual:(id)object;
+- (id)retain;
+- (oneway void)release;
+@end
+@protocol NSCopying
+- (id)copyWithZone:(NSZone *)zone;
+@end
+@protocol NSCoding
+- (void)encodeWithCoder:(NSCoder *)aCoder;
+@end
+@interface NSObject <NSObject> {}
+- (id)init;
++ (id)alloc;
+@end
+typedef double NSTimeInterval;
+enum { NSAnimationEaseInOut, NSAnimationEaseIn, NSAnimationEaseOut, NSAnimationLinear };
+typedef NSUInteger NSAnimationCurve;
+@interface NSAnimation : NSObject <NSCopying, NSCoding> {}
+- (id)initWithDuration:(NSTimeInterval)duration animationCurve:(NSAnimationCurve)animationCurve;
+- (void)startAnimation;
+- (void)setDelegate:(id)delegate;
+@end
+
+// END delta-debugging reduced header stuff
+
+// From NSAnimation Class Reference
+// -(void)startAnimation
+// The receiver retains itself and is then autoreleased at the end 
+// of the animation or when it receives stopAnimation.
+
+@interface MyClass { }
+- (void)animationDidEnd:(NSAnimation *)animation;
+@end
+
+@implementation MyClass
+- (void)f1 {  
+  // NOTE: The analyzer doesn't really handle this; it just stops tracking
+  // 'animation' when it is sent the message 'setDelegate:'.
+  NSAnimation *animation = [[NSAnimation alloc]   // no-warning
+                            initWithDuration:1.0 
+                            animationCurve:NSAnimationEaseInOut];
+  
+  [animation setDelegate:self];
+  [animation startAnimation]; 
+}
+
+- (void)f2 {
+  NSAnimation *animation = [[NSAnimation alloc]  // expected-warning{{leak}}
+                            initWithDuration:1.0 
+                            animationCurve:NSAnimationEaseInOut];
+
+  [animation startAnimation]; 
+}
+
+- (void)animationDidEnd:(NSAnimation *)animation {
+  [animation release];
+}
+@end